Superchargers may be used to increase or “boost” the air pressure in the intake manifold of an internal combustion (IC) engine to increase the horsepower output of the IC engine. The IC engine may thus have an increased horsepower output capability than would otherwise occur if the engine were normally aspirated (e.g., the piston would draw air into the cylinder during the intake stroke of the piston). A conventional supercharger is generally mechanically driven by the engine, and therefore, may represent a drain on engine horsepower whenever engine “boost” may not be required and/or desired. A selectively engageable clutch may be disposed in series between the supercharger input (e.g., a belt driven pulley) and the rotors of the supercharger. A transmission may be disposed in series between the clutch and the rotors of the supercharger.